This paper presents initial, positive results from using SPARK to prove critical properties of OpenUxAS, a service-oriented software framework developed by AFRL for mission-level autonomy for teams of cooperating unmanned vehicles. Given the intended use of OpenUxAS, there are many safety and security implications; however, these considerations are unaddressed in the current implementation. AFRL is seeking to address these considerations through the use of formal methods, including through the application of SPARK, a programming language that includes a specification language and a toolset for proving that programs satisfy their specifications. Using SPARK, we reimplemented one of the core services in OpenUxAS and proved that a critical part of its functionality satisfies its specification. This successful application provides a foundation for further applications of formal methods to OpenUxAS.